The invention relates to any remote-controllable, programmable, hearing aid system, e.g., as disclosed in U.S. Pat. No. 4,947,432.
In this system, a basic transmission characteristic is permanently set in the actual hearing aid in the individual stages of the transmission channel from the microphone to the earphone. Other transmission characteristics are stored in an external control unit and can be optionally selected by operation of a switch or pushbutton and transmitted to the receiver provided in the hearing aid by means of a transmitter incorporated in the external control unit.
After demodulation and corresponding processing, the signals picked up by the hearing aid serve the purpose of setting a different transmission characteristic of the hearing aid between the microphone and earphone for adaptation to one of several environmental situations digitally stored in an external control unit, for example in the form of control parameters.